Commercial automotive child restraint systems (CRSs) do not accommodate all children with special healthcare needs. This study developed an alternative harness for a commercial CRS to meet the needs of children for whom a five-point harness cannot be positioned over medically involved areas and/or children whose conditions require the harness belts to be threaded through medical devices. After initial design work and a series of frontal sled-impact tests, one of two prototype designs was chosen for fit testing on children with and without healthcare conditions. After a minor modification, additional sled-impact testing was conducted to determine compliance of the system to federal standards. The CRS with alternate harness provides good fit to children with a variety of healthcare needs and complies with all performance criteria of FMVSS 213, with the exception of peak forward head excursion using the Hybrid III 6-year-old crash-test dummy. It is expected that all performance criteria will be met using the newly-issued federal allowance to conduct CRS frontal-impact tests using an earlier version of the dummy. The new harness shows promise as a low-cost solution for achieving a safer level of transportation for children who may otherwise travel unrestrained or with a severely misused CRS harness.